Sorry to bring this up again, but I found lotr_freak's explanation from Modern I:

lotr_freak wrote:

metallord99 wrote:

Waterice man wrote:Can I enquire as to the purpose of the railway line type thing connecting the Black and Caspian Sea

so that means if I have a fleet in the Caspian I can move it in 1 turn to Ros?

As King Jeff pointed out, it means that there is a canal from Cas to EBS. It doesn't mean you can move there in one turn, it just means that there is a connection. A fleet could move from Cas to Vol, then from Vol to Ros, and then from Ros into EBS. But it would take 3 turns total.

There are two other canals on the map, in Ham (northern Germany) and in Cai (Egypt). In essence, these mean that those territories do not have coasts, so fleets may pass directly through them. It still takes a move to go through though. For example, you could move from Hel to Ham, and then from Ham to Bhm (or Ber) the next turn. Or Cai could move directly into Red, Sin, or Isr, from where it is right now.